Head-to-head · Best Backpacking Sleeping Bags

Exped Terra 15 vs Kelty Cosmic Down 20

Which is the better buy? Side-by-side on rating, price, strengths, and watch-outs — with the published ratings we averaged to get there.

The short answer

Exped Terra 15 comes out ahead by a clear margin (4.2 vs 3.9). The gap is mostly about weekend warriors seeking comfort — read the strengths below before deciding.

Higher ratedRanked #2 in Best Backpacking Sleeping Bags

Exped Terra 15

4.2

$109.95as of Jul 1

The Exped Terra 15 Sleeping Bag offers a compelling balance of warmth, weight, and affordability for 3-season backpacking use. REI's Emily Pennington praised its 650-fill down insulation, soft fabric, and practical features like the draft collar and 3D footbox. The bag is designed for middle-of-the-road sleepers and comes in five sizes to accommodate different body types. While it's well-suited for summer and early fall camping, ultralight enthusiasts may find it slightly heavier than their ideal setup. It's best for weekend warriors and backpackers seeking a budget-friendly option without sacrificing comfort.

Strengths

— Soft recycled 20-denier ripstop polyester shell and liner with OEKO-TEX® STANDARD 100 certification
— Adjustable draft collar and hood help retain warmth and prevent heat loss
— 3D footbox design allows better blood flow and keeps toes warm during sleep

Watch-outs

— Stuff sack is described as bulky despite compression
— Unisex sizing may not fit those who run cold well

$109.95 · Check Price on Amazon Full review →

Ranked #3 in Best Backpacking Sleeping Bags

Kelty Cosmic Down 20

3.9

$157.39as of Jul 1

The Kelty Cosmic Down 20 offers budget-friendly down insulation with a mummy shape that provides spacious shoulders but tight hips and feet. Reviewers noted its 550-fill down is less thermally efficient than pricier alternatives, making it better suited for summer camping and mild conditions. While it's more durable than ultralight options due to its thicker shell fabric, the bag's weight and bulk are drawbacks. It's recommended for casual backpackers seeking real down without breaking the bank, but those expecting sub-freezing temperatures should look elsewhere.

Strengths

— More packable than most budget options with synthetic fill
— Spacious dimensions despite tapered mummy shape
— Relatively thick polyester fabric is more resilient than thin ultralight material

Watch-outs

— Cut-rate 550-fill down places it at the low end for warmth-to-weight
— Runs colder than its temp rating in real-world testing

$157.39 · Check Price on Amazon Full review →

How they stack up

Exped Terra 15

The Exped Terra 15 offers a good balance of affordability and comfort, outperforming the Kelty Cosmic Down 20 in warmth and fabric quality, though it's heavier than the Mountain Hardwear Phantom 30. Compared to the Western Mountaineering MegaLite, it's less expensive but lacks the ultralight design and spaciousness.

Kelty Cosmic Down 20

The Kelty Cosmic Down 20 provides more packability and durability than the budget-friendly Exped Terra 15, but it's less warm than the Argali Alpine 20. Unlike the REI Trailmade 25, which offers better value and sizing, the Kelty bag is more suitable for casual campers who want real down without premium pricing.

Specs side-by-side

Spec	Exped Terra 15	Kelty Cosmic Down 20
Temperature Rating	15°F comfort	31/21°F (ISO Comfort/Limit)
Fill Power	650-fill-power	1 lb. 0.4 oz. of 550-fill down
Weight	2 lbs 10.5 oz (S)	2 lb. 7 oz.
Shape	Mummy	Semi-Rectangular
Insulation	650+ cuin/oz European Grey Duck Down	550-fill-power down
Shell Fabric	Recycled 20 D ripstop polyester	20D nylon
Packed Volume	—	10.7L

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